Coupler compounds that form yellow image dyes upon coupling with the oxidation products of p-phenylendiamine color developing agents are described in such patents and literature as U.S. Pat. Nos. 2,298,443, 2,407,210, 2,287,057, 3,048,194, 3,265,506, 3,447,928, 4,022,620, and 4,443,536; and "Farbkupplereine Literature Ubersicht" published in Agfa Mitteilungen, Band III, pp. 112-126 (1961). The ability of the yellow image dye to resist light fading is important to the longevity of the color image, especially those images that are exposed to light over long periods of time, such as professional portraits.
U.S. Pat. No. 5,677,114 discloses improved stability to light fading of the yellow image dye by incorporating a ballast group comprising a stabilizing group in the yellow dye-forming coupler. Still further improvement in the resistance to fading of yellow dyes is desired for modem color photographic papers.
Therefore, a problem to be solved is to provide a dye-forming coupler capable of forming, upon coupling with the oxidation product of a p-phenylenediamine color developer, a yellow image dye having improved resistance to fading after prolonged and constant exposure to light. The need for such a coupler is especially great for use in photographic color paper for forming reflection prints of excellent light fading stability.